Mold blowing apparatus



March 17, 1959 H. J. B. HERBRUGGEN I 2,877,522

v MOLD BLowING APPARATUS Filed April 14, 1955 GvSheets-Sheet 1 March 17,1959 H. J. B. HERBRUGGEN 2,877,522

MOLD BLOWING APPARATUS Filed April 14, 1955 6 Sheets-Sheet 2 INVENTOR.

,Morne/s March 17, l959- H. J. B. HERBRUGGEN 2,877,522

MOLD BLOWING APPARATUS Filed April 14, 1955 6 Sheets-Sheet 3 March 17,1959 H. .J. B; HERBRUGGEN Mom BLowrNG APPARATUS 6 Sheets-Sheet 5 FiledApril 14. 1955 INVENToR.

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United States Patent() MLD BLOWING APPARATUS Application April 14, 1955,Serial No. 501,287 4 Claims. (Cl. 22-36) This invention relates to theart of making sand molds, cores and the like and more particularlyrelates to improvements in apparatus for forming sand molds and cores byblowing sand into an enclosed cavity.

The improvements of this invention are particularly adapted for use in asand blowing apparatus of the type in which sand is discharged from achamber by means of an air stream and into a mold cavity formed by theask, a top plate and a bottom pattern plate until the cavity iscompletely filled with sand. In simple molding, the drag and copeportions of the mold are usually formed independently in the apparatuswhich includes an arrangement for compacting the sand in each ask portion so that the completed mold or core will resist deformation underpressure by the poured metal.

A principal object of this invention relates to the pro-I j l ternc'arrier and lift table assembly; and

2,877,522 Patented Mar. 17, 1959 umn illustrating the movable supportfor the spacer memspaced arms like 19 ber;

` Fig. 5 is a partial vertical section illustrating the position of theoperative members in the flask receiving area prior to clamping;

Fig. 6 is a partial vertical section illustrating the position of theoperative members in the ask receiving area during the sand blowingoperation;

- Fig.Y 7 is a partial front elevation illustrating the pat- Fig. 8 is avertical section illustrating the position of the operative members inthe flask receiving area after removal of the spacer member and prior tocompacting.

Referring now more particularly to Fig. 1 of -the drawings, there isshown a sand blowing apparatus for making molds or cores and embodyingan upright frame having a base 10 supporting spacedv vertical columns 11and 12 which are connected together at the top by a cross head 14. Asand discharge chamber 15 having a removable blow plate assembly 16 ispivotally supported by which are swingable about the column 12 toposition the chamber 15 under a sand hopper 20 external to the frame.The base 10 also supports spaced flask rails 22 and 23 for receiving acope or drag g ask in' aligned position beneath the sand chamber 15.

" Although not shown,

dling and increases production eiciency by permitting the pattern to bechanged on one portion of the `carrier while another mold or core isbeing formed on another part of the carrier.

Another principal object'of this invention relates-to'a simplificationin the apparatus for compacting sand in the flask or core box.

Briefly, in accordance with this invention a sand discharge chamber isoperably supported on a frame in surmounting spaced relation over aflask lift table to define a flask receiving area therebetween. Theframe also supports a movable multiple pattern carrier for presenting aselected pattern onto the lift table while removing another patterntherefrom. The mold or core is formed by discharging sand from thechamber into the mold cavity formed when the lift table clamps the flaskagainst the discharge portion of the chamber. A spacer member is alsomovably supported on the frame for insertion between the sand dischargechamber and the ilask and operates to increase the sand receiving volumeof the mold v cavity. After sand is discharged into the enlarged' moldcavity, the spacer member may be removed 'andthe sand compacted in thetiask or core box by repeatingthe' clamping action of the lift table toform a sand mold or core capable of resisting deformation under pressureof poured metal. Different spacer members may be used to vary thedensity of the sand. In conjunction with the -fore-v going, the lifttable is controlled during removal of the spacer member to preventseparation of the mold from the pattern.

Additional objects and advantages of the improvements embodied in thisinvention will be apparent from the following description, the appendedclaims and the ac-f` Fig. 2 is a horizontal section taken along theplane of the ask supporting rails with the liask removed in Fig. 1;`

Fig. 3 is a plan view of an interchangeable spacer memb'er forincreasing the mold cavity volume;

the rails 22 and 23 may be provided with extensions to support a line'ofasks or core boxes for successive presentation to the core blowingapparatus. Movement of the line would be periodically lnterrupted duringthe sand blowing operation and then resumed to present an empty ask orcore box above the t table 25 while the completed mold or core isdischarged at the other end of the line. The ask lift table 25 issupported on a movable main plunger 26 in alift cylinder 27 which isdisposed'within the base for operation in a conventional manner (Pigs. 6and 8). The lift table 25 is also provided with an auxiliary plunger 30at its forward extremity which is disposed in a cylinder housing 31forming part of the base 10. The main plunger 26 and the spacedauxiliary plunger 30 coact on the base to prevent rotation of the table25 and are operated by hydraulic pressure of oil or Ythe like to controlthe movement of the lift table in a manner to be hereinafter more fullydescribed. Y

In normal operation, a drag pattern 17 or a cope pat- L terncorresponding to the type of liask 13 mounted on the rails 22 and 23would be positioned above the lift table 25 and uid under pressureapplied to lift the pat tern and flask against the blow-plate assembly16 of the sand chamber to form a Vsand receiving mold cavity as shown inFig. 6. Blowing pressure is supplied'to the chamber 15 through suitableconduits like 33 and' con? trol valves like 34 which may be controlledat the control panel 35 to discharge sand from the chamber 15 into themold cavity. After formation of the mold or core i has beenaccomplished, the control valves can be op-V erated to terminate theblowing cycle and exhaust the chamber 15 through the stack 36. Thecontrols may be selectively manipulated or maybe coupled together toAprovide an automatic sand blowing cycle.

In order to increase the eliciency and production of the apparatus, thepatterns are mounted on plates 38 and 39 respectively and each plate isin turn mounted in xed predetermined position ona multiple patterncarrier assembly which can be moved to selectively position either thedrag or the cope pattern plate below the flask rails 22 and 23 and abovethe lift table 25.

Referring now particularly to Fig. 2 in conjunction with Fig. 1, thepattern'carrier assembly is shown as em Jbodying a support 40 having apair of legs 41 and 42 dis-A posed at right angles to each other andmounted for' rotation about the column 12 with its vertex coincidentwith the vertical axis of the column. Each leg of the support 40 carriesan open-ended :frame 44 and 45 and the length of each -leg .is selectedlso vthat the path of travel of each -frame 'will intersect the lifttable 25 when the support 40 is rotated. The frames 44 and 45 have `asubstantially `U-shaped conguration which is complementary to theperiphery of the lift table 25. Their open ends face inwardly towardsthe lift table .so that when they are rotated `in the plane of the table25 they `will partially encircle the table and support the correspondingpattern above the table. Each vframe pattern carrier is provided withsuitable pattern location holes 46 and `47 which are adapted to receivepattern plate guide pins, .and the lift table 25 is -also 'provided`with suitable dowel pins 48 and 49 for alignment with correspondingguide openings .in the pattern vplates all of which reduces time andeiort in handling.

The mounting .of the support 40 on the column 12 is accomplished byencircling the column 12 with a rotatable sleeve 50 which `carriesradiallyprojecting :arms '51 and 5 2 vto which the support 40 isconnected. With this arrangement, while oneppattern and flask areclamped fin sand blowing relation with the chamber ,15 and a mold orcore is being formed, an operator can be preparing another pattern onthe other carrier for presentation to -the sand blowing apparatus.Usually, in simple molding, the drag pattern would `be mounted on onecarrier vand the cope pattern on the-other carrier so that 'the twohalves of the `mold could be made in rapid succession. The. patterncarrierassemblymay be rotated on the column 12 by hand, or as shown inpreferred form in the drawings, may be positioned by locating a motor 55on a platform S6 on .the basel 10 andproviding .a friction wheel 58 onthe motor `shaft to Afr-ictionally engage .and rotate the carriersupport 40 about its axis. The driving motor 55.may -be energizedthrough the medium of-.conventional reversing `switches toautomaticallypresent selected ,pa-tterns in predetermined sequence.

After the .ilask vor core box 13 has been -lled with sand, the sand maybe compacted so that it will resist deformation under pressure of pouredmetal. In accordance with this invention, the compacting is preferablyaccomplished by introducing a spacer plate 60 between the top of theilask 13 and the blow-plate assembly 16 of the sand chamber to increasethe sand receiving volume of the mold cavity (Fig. 6). After theenlarged cavity is filled with sand to a certain density, the spacerplate 60 is removed and the lift table 25 clamps the bottom patternplate and the flask 13 against the blow plateassembly to compact thesandin the reduced cavity. The density of the compacted sand will depend.upon the excess sand volume as determined by the thickness of thespacer plate `60. Hence, the sand density can be varied by `usingdifferent spacer plates. This eliminates the necessity for extra squeezeplatens and results in a similar design and more efhcient operation.

The spacer plate 60 is of uniform thickness and has Van opening 62corresponding substantially to the boundary area defined by the walls`of the ask 13 and is adapted to be aligned therewith. `4Since thespacervplate 60-and its opening 62 may vary with the desired sanddensity as well as the size and type of ask, provision is made toremovably support any type of spacer plate in the work space between theflask vand the chamber blow plate assembly. This provision includes aU-.shaped .member 63 which is carried by a sleeve .64 concentricallymounted on the column 11 and rotatable on suitable `bearings Vas bestshown in the partial section view 4in Fig. 4 offthe drawings. The member63 carriessuitable dowel pins 66 and 67 which are adapted for alignmentwith openings 68 and 69 in the spacer plate 60.

Thus, once a particular ask 13 is placed on the ask rails 22 and 23above the corresponding pattern .plate and 'before the lift table 25 `isactivated, the spacer plate .60 is swung about the column 11 into thespace bethe lift table 25f1owers the bottom pattern plate and the flaska distance suicient to permit removal of the spacer plate 60 by swingingItlre'member 63 outwardly about the column -11 and to leave `a'volume ofsand in excess 'of the reduced cavity defined by the lflask walls andthe bottom pattern plate as best shown in Fig. 8 of lthe drawings. Thelift table 25 is again moved to clamp the bottom pattern plate and flaskagainst the blow plate assembly and the sand is compacted in the reducedcavity thus formed. After the squeezing operation, the lift tablereturns and deposits themold on rails 22 and withdraws the pattern. AsYwill `hereinafter be more fully ex plained, the draw speed is decreasedduring separation to protect the mold. Although the foregoingoperations. may be accomplished by hand, the foregoing operations can be.automatically 1accomplished in predetermined sequence in a continuoussand blowing cycle ,by means of suitable conventional controls.

Since it is necessary to lower the lift table 25 suiciently to permitremoval of the spacer plate 60 prior to the cornpacting operation, itwill be apparent that in the construction of the apparatus disclosedthere -must be a limit to the extent that the lift table may be loweredin order` to prevent separation of the pattern rplate 4vfrom the flask(see Fig. 7,). This is preferably accomplished in .accordance with thisinvention by controlling release of hydraulic uid from the cylinderhousing 31 in such `a manner `as to provide a dashpot operation for theplunger 30. Thus, initially when fluid under pressure is applied to liftthe table 25 it may :also be supplied to the cylinder 31 and, after themold cavity is filled with sand and the main plunger v26 Vis lowered,the hydraulic uid is blocked `in the cylinder 31 to provide a limitingdownward stop for lift table 25. The same arrangement is utilized todecrease the draw vspeed of the lift table during separation of thepattern from the mold. Operation of the dashpot can be controlled byconventional valves and the like and by adjusting the stroke of theplunger 30 in the cylinder 31.

Thus, there has been providedan improved sand blowing apparatus formaking sand molds and cores or the.

like an-d having a more eilicient and highly productive arrangement forpresenting the `proper patterns and for removing and unloading thecompleted molds or cores. There has also been provided a simplearrangement for utilizing the main lift table in conjunction with aspacer member to permit compacting of the sand within the mold cavity.The latter arrangement includes an Virnproved .dashpot type limit forthe lift table movement to prevent separation of the pattern from themold while the spacer plate is being removed prior to the sandcompacting operation and to reduce the draw speed during separation ofthe pattern from the mold. The improved apparatus permits the making ofcope and drag on a single `machine and provides greater accessibilityfor inspection `and replacement of patterns during operation. Each ofthese improvements contribute to the overall efliciency and to increasedproduction in a manner that results in the optimum formation of sandmolds and cores which are sutliciently compressed to withstand metalpressures in later use.

I have shown and described what l consider to be theV preferredembodiment of my invention along with suggested modied forms, and it isclear that other changes and modifications may be made by those skilledvention as defined by the appended claims.

l claim:

1. ln a sand blowing apparatus having a frame including a patternsupport adapted to be surmounted by a ask or core box, a multiplepattern carrier rotatably mounted on the frame and adapted to supportindependent patterns in spaced relation from each other, said carrierhaving at least a pair of circumferentially displaced carrier portionseach adapted to independently support a pattern thereon, thedisplacement being such that while one pattern is positioned by thecarrier in operative position on the pattern support at least anotherpattern is accessible to an operator external to the support and frame,said pattern support comprising a lift table adapted for verticalmovement relative to the frame, each of said carrier portions includingan open-ended frame disposed with the open ends facing each other onopposite sides ofthe lift table, each of said open-ended frames deinng,

a boundary complementary to the peripheral configuration of the lifttable, whereby vertical movement of said table will lift the patternaway from the carrier and towards the surmounting ask or core box.

2. In a sand blowing apparatus having a frame including a verticalcolumn disposed adjacent a pattern support, said pattern suport beingadapted to be surmounted by a. ask or core box, a multiple patterncarrier rotatably mounted on the frame column and adapted to supportindependent patterns in spaced relation from each other, said carrierhaving at least a pair of circumferentially displaced carrier portionseach adapted to independently support a pattern thereon, each of saidcarrier portions comprising an open ended frame dening a boundarycomplementary to the peripheral conguration of the pattern spaced sanddischarge chamber and a bottom pattern eleed to independently support apattern placement being such that when one pattern is positioned by thecarrier in operative position with respect to the clamping member atleast another pattern is accessible to an operator external to theclamping member and each of said open-ended frames dening a boundarygenverally complementary to the peripherial configuration of theclamping member, a spacer member, means rotatably mounted on saidapparatus frame above said ask or core kbox support and above saidcarrier for supporting said spacer member in a plurality of positionswith respect to said sand receiving cavity, said spacer member beingselectively movable into and'out of the space between the dischargechamber and sand receiving cavity depending upon the direction ofrotation of said means and being vertically movable with respect to thelatter when engaged by said iiask or core box, saidspacer member havingan opening therethrough of a coniguration substantially coincident withthe ask or core'box walls of the sand receiving cavity when said meansis rotated to position said spacer member into said space, whereby thevolume of the enclosed cavity is increased bythe thickness of the spacermember, said clamping member being operative upon upward movementthereof to lift the pattern element away from said carrier, the ask vorcore box away from its support, and the spacer member away from itssupporting means, all towards said sand discharge chamber, and

claim 3 wherein said rality of vertical columns disposed generallyadjacent said -said spacer member there aek or core box, and meanson`said spacer plate adapted lfor interlocking coaction in a means forselectively limiting retraction of said clamping member to permitoutward rotation of said spacer mem- I.her supporting means andresultant removal of the spacer l member from said y,element from theing member may space without separation of the pattern ilask or corebox, whereby said clampbe reapplied to compact the sand in the lessersand receiving cavity with the spacer member removed.

v4. In a sand blowing apparatus in accordance with vapparatus framecomprises a plu- `clamping member, said carrier being rotatably mountedon one of said columns, said spacer member supporting means beingrotatably mounted on another of said columns, said spacer memberrsupporting means comprising a sleeve element concentrically mounted inmovable re- .lationship on said othercolumn and a generally horizontallyextending U-shaped arm element for supporting lon, said spacer membercomprising an interchangeable spacer plate having an openingcorresponding to the particular type and size of associated said armelement and on horizontal plane to align the spacer plate opening withthe flask or core box opening.

References Cited in the le of this patent UNITED STATES PATENTS1,021,938 MacKay Apr. 2, 1912 1,367,079 Nicholls Feb. 1, 1921 1,740,766Campbell Dec. 24, 1929 2,012,478 Oyster Aug. 27, 1935 2,489,810 OysterNov. 29, 1949 2,632,215 Lee Mar. 24, 1953 FOREIGN PATENTS 543,832Germany Feb. 15, 1932 824,543 Germany Dec. 13, 1951

